HYGROSCOPIC BALANCE IN PUMPKIN SEEDS

Abstract

The commercial exploitation of pumpkin seeds, at the flour form toasted or to the production of oil, requires knowledge about the activity of water and equilibrium moistures. This study aimed to determine the equilibrium isotherms to the pumpkin seeds and describe the dynamics of the process upon its physicochemical quality. With the static method, the equilibrium isotherms were determined for different temperatures and activities of water (0.110 to 0.885 dry basis), provided conditions by the conditioner chamber of atmosphere, with the weighing of the samples until the constant mass. The hygroscopic balance of the seeds was directly proportional to the activity of water and decreased with increasing temperature, for the same value of water activity. The pumpkin seeds maintained the water volume (<0.10) at the storage conditions (relative humidity < 25 %). The modified Halsey model better represented the hygroscopicity of pumpkin seeds.